This invention relates generally to electrical power generating systems and more particularly to an electrical power generating system wherein a generator output is controlled by simultaneously controlling the generator excitation and the speed of a prime mover.
Systems for controlling the output of an electrical generator driven by a prime mover have been in use with large generators and prime movers for some time. For example, in U.S. Pat. No. 3,878,400 to McSparran, a diesel electric locomotive has an excitation control system for a generator driven by the diesel engine. The generator excitation is controlled in response to generator output voltage and current, an error signal computed by comparing generator power output with a reference circuit output, engine rotor speed and engine temperature. Additionally, as illustrated in U.S. Pat. No. 3,340,883 to Peternel, it is known to control input energy to a prime mover in response to the load on the generator driven by that prime mover.
Such prior systems have been quite large and quite costly. To date, no prior system has been developed which, on a cost effective basis, can provide standby electrical power or auxiliary electrical power on a relatively small scale and with the same or greater degree of control as in such prior large scale systems.
Accordingly, it is an object of the present invention to provide an improved electrical generating control system for engine driven generators.
Another object of the present invention is the provision of such a control system especially suitable for small scale power generation for use as standby or auxiliary power.
It is a further object of the present invention to provide an improved control system for an engine generator set to permit a more sophisticated degree of control than has heretofore been obtainable.
Yet another object of the present invention is the provision of such a control system including safety features to protect the user and the system against unsafe or damaging conditions.
It is another object of the present invention to provide such a control system that is both economical and relatively easy to manufacture.